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Updated: May 4, 2026
The Replica Set Method: A High-throughput Approach to Quantitatively Measure Caenorhabditis elegans Lifespan
Published on: June 29, 2018
Germline signaling mediates the synergistically prolonged longevity produced by double mutations in daf-2 and rsks-1
Di Chen1, Patrick Wai-Lun Li2, Benjamin A Goldstein3
1MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Pukou District, Nanjing, Jiangsu 210061, China.
Abstract:
Inhibition of DAF-2 (insulin-like growth factor 1 [IGF-1] receptor) or RSKS-1 (S6K), key molecules in the insulin/IGF-1 signaling (IIS) and target of rapamycin (TOR) pathways, respectively, extend lifespan in Caenorhabditis elegans. However, it has not been clear how and in which tissues they interact with each other to modulate longevity. Here, we demonstrate that a combination of mutations in daf-2 and rsks-1 produces a nearly 5-fold increase in longevity that is much greater than the sum of single mutations. This synergistic lifespan extension requires positive feedback regulation of DAF-16 (FOXO) via the AMP-activated protein kinase (AMPK) complex. Furthermore, we identify germline as the key tissue for this synergistic longevity. Moreover, germline-specific inhibition of rsks-1 activates DAF-16 in the intestine. Together, our findings highlight the importance of the germline in the significantly increased longevity produced by daf-2 rsks-1, which has important implications for interactions between the two major conserved longevity pathways in more complex organisms.
Insights
Combining mutations in DAF-2 and RSKS-1 dramatically extends lifespan in C. elegans by activating DAF-16. The germline is identified as the key tissue mediating this synergistic longevity effect.
Area of Science:
- Gerontology
- Molecular Biology
- Genetics
Background:
- The insulin/IGF-1 signaling (IIS) and target of rapamycin (TOR) pathways regulate lifespan.
- Inhibiting DAF-2 (an IIS component) or RSKS-1 (a TOR component) extends longevity in C. elegans.
- The interaction between these pathways and tissues modulating longevity remains unclear.
Purpose of the Study:
- To investigate the synergistic effect of inhibiting both DAF-2 and RSKS-1 on lifespan.
- To identify the molecular mechanisms and tissues involved in this synergistic longevity.
- To explore the implications for conserved longevity pathways.
Main Methods:
- Utilized Caenorhabditis elegans as a model organism.
- Generated combined mutations in daf-2 and rsks-1.
- Investigated the role of AMP-activated protein kinase (AMPK) and DAF-16 (FOXO).
- Performed tissue-specific inhibition experiments, focusing on the germline.
Main Results:
- A combination of daf-2 and rsks-1 mutations resulted in a nearly 5-fold increase in lifespan, exceeding the additive effects of single mutations.
- Synergistic lifespan extension was dependent on positive feedback regulation of DAF-16 via the AMPK complex.
- The germline was identified as the critical tissue responsible for this synergistic longevity.
- Germline-specific inhibition of rsks-1 led to the activation of DAF-16 in the intestine.
Conclusions:
- The germline plays a crucial role in the synergistic lifespan extension observed with combined daf-2 and rsks-1 inhibition.
- Interactions between the IIS and TOR pathways, particularly involving the germline, significantly impact longevity.
- These findings have implications for understanding longevity regulation in more complex organisms.
